<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
</head>

<body>
    <div id="app">
        <p>{{msg}}</p>
    </div>
    <button>改变</button>
    <a href="#">获取数据</a>
    <p id="pinner"></p>
</body>
<script>
    const obj = {
        msg: "hello world!"
    }
    const app = new Vue({
        el: "#app",
        data: obj
    })
    document.getElementsByTagName("button")[0].onclick = () => {
        obj.msg = "按钮点击事件..."
    }
    console.log(document.getElementsByTagName("a")[0])
    document.getElementsByTagName("a")[0].onclick = (evt) => {
        evt.preventDefault();
        document.getElementById("pinner").innerHTML = app.msg;
    }
</script>

</html>